The invention relates generally to exercise devices, and more particularly to a device for use in an exercise where the user rotates a pair of grips.
One type of exercise device employs a friction clutch to resist rotation of hand grips. An example of such a device is described in U.S. Pat. No. 4,203,591.
Other exercise devices employ springs to provide relative resistance between a pair of axially aligned hand grips. An example of this type of device is described in U.S. Pat. No. 4,095,789.
One difference between the friction device and the spring-loaded device is that in the latter, the springs maintain torque in a predetermined direction on the grips through a predetermined range of motion, regardless of whether the grips are being rotated, whereas in the friction device, the friction clutch only applies torque to a grip during rotation of the grip, in a direction opposite to rotation of the grip. Thus, with the latter type of device, when the user rotates a grip in reciprocating motion, the muscles are able to apply force in a single rotational direction while moving alternately in opposite directions.
In devices having aligned rotatable grips, when the user applies torque to one of the grips, he or she must apply oppositely-directed torque of equal magnitude to the opposite grip in reaction thereto. The user accordingly cannot apply torque to either grip in excess of the torque he is capable of applying to the other grip in the opposite direction. The present invention pertains to a device which is not so limited, and which is believed to provide various other advantages over the prior art.
Accordingly, it is a general object of the present invention to provide an improved exercise device of the type having rotatable hand grips and means for providing resistance to rotation thereof.
It is an additional object of the present invention to provide an exercise device which is relatively economical to manufacture, relatively compact, and adjustable to permit variation of resistance to twisting of hand grips.
Further objects and advantages of the invention will become apparent from the detailed description set forth below, and the accompanying drawings.